1. Field of the Invention
The present invention relates to a liquid cartridge including a board mounting section for mounting a circuit board on an outer side of the main body of a liquid container and a method for manufacturing the same.
2. Description of the Related Art
Inkjet printers are discussed below as an example of a more general class of devices that may be described as liquid consuming apparatuses, and the comments made below with respect to inkjet printers should be understood to apply as well, in the main, to liquid consuming apparatuses. Inkjet printers generally record images or characters by feeding a recording head with ink held in an ink cartridge (a liquid cartridge) mounted to a cartridge mounting section in the apparatus and by applying a jet of ink droplets onto a recording object, such as paper, with the recording head.
The recording heads of inkjet printers control a jet of ink droplets, most commonly using heat or vibration. Accordingly, if the ink cartridge runs out of ink to carry out an ink ejecting operation with no ink supplied, the recording heads will malfunction, possibly being damaged or rendered unusable by a typical user.
Accordingly, for inkjet printers, it is necessary to monitor the ink level of the ink cartridge so as to prevent the recording head from attempting to perform an ink ejecting operation with no ink.
Furthermore, different use conditions such as full-color picture printing and single-color text printing lead to differences in the color and amount of ink consumed.
Therefore, some recent inkjet printers adopt ink cartridges, part of which can be changed so as to meet the use conditions. Such inkjet printers need to manage use history or the like, such as whether the ink cartridges mounted to the cartridge mounting section are new ones or reused ones.
The reader's attention is now drawn to ink cartridges 1 and 2 shown in FIGS. 8A and 8B and FIGS. 9A and 9B. Such cartridges have been proposed to help cope with the situation described above. The ink cartridges 1 and 2 have a container main body 4 composed of a case main body 5 including an ink reservoir 5a and a supply port 5b for supplying the ink in the ink reservoir 5a to an external device (the recording head of the inkjet printer) and a cover 6 covering one side of the case main body 5.
The container main body 4 has, on an outer side, a recess (also referred to a board mounting section) 11 for mounting a circuit board 9 (see FIG. 9B) having an information storage element (such as an IC chip) 8 on the back.
The surface of the circuit board 9 (opposite to the surface having the information storage element 8) has a connecting terminal that electrically connects the information storage element 8 to a connecting terminal mounted to the cartridge mounting section by connecting to the connecting terminal when the ink cartridges 1 and 2 are mounted to the cartridge mounting section of the inkjet printer.
The recess 11 has a pair of board fixing bosses 12a and 12b that fit in the mounting holes of the circuit board 9 to locate the circuit board 9, and four walls 13a to 13d erected along the peripheral four sides of the circuit board 9 located by the pair of board fixing bosses 12a and 12b. The circuit board 9 located by the board fixing bosses 12a and 12b is fixed in the recess 11 by swaging the ends of the board fixing bosses 12a and 12b with heat.
The four walls 13a to 13d are for preventing the connecting terminal (or the like) on the surface of the circuit board 9 from coming into contact with an external structure or the like, which undesired contact might result in staining when the cartridge is attached or detached. The heights of the walls 13a to 13d are set so that the connecting terminal on the surface of the circuit board 9 does not protrude from the ends of the walls 13a to 13d. 
The ink cartridges 1 and 2 have the same structure in which the case main body 5 and the cover 6 are resin injection-moldings and the recess 11 is disposed on an outer side of the case main body 5.
However, in the case of the ink cartridge 1 shown in FIGS. 8A and 8B, the recess 11 is integrally formed in the case main body 5 using a sliding die 15 separate from upper and lower dies (a pair of dies), as shown in FIG. 8B (for example, refer to JP-A-2001-180003).
In contrast, in the case of the ink cartridge 2 shown in FIGS. 9A and 9B, the recess 11 is defined by a frame 17 that is injection molded separately from the case main body 5, and the frame 17 is integrated with the case main body 5 with recess positioning bosses 18a and 18b protruding from an outer side of the case main body 5 (for example, refer to JP-A-2004-90624).
When the ink cartridges 1 and 2 are mounted to the cartridge mounting section of an inkjet printer, information can be exchanged between the control means of the printer and the information storage element 8 of the circuit board 9, thus facilitating managing the amount of remaining ink by the printer.
However, in the case of the ink cartridge 1 shown in FIGS. 8A and 8B, the sliding die 15 that slides in the direction perpendicular to the removing direction of the upper and lower dies must be combined with a forming die for use in manufacturing the case main body 5, thus causing complication of the forming die to increase the cost.
In contrast, in the case of the ink cartridge 2 in which the recess 11 is formed by the frame 17 separate from the case main body 5, although the forming die for the case main body 5 has a simple structure with no sliding die, another forming die for the frame 17 is needed and the process of combining the frame 17 with the case main body 5 is added, and thus the increase in the number of dies and the increase of the combining process causes an increase in cost and a decrease in productivity.